1. Technical Field
The present invention relates to an image reading apparatus.
2. Related Art
JP-A-2006-314039 discloses an image reading apparatus (scanner) that reads an original image using an image sensor, converts the image signal obtained by reading into digital image data using an analog front end (AFE), and outputs the converted digital image data to a digital processing unit or a data transfer unit.
JP-A-2006-314039 is an example of related art.
Since various types of scanners such as sheet-feeding and flat-feeding scanners exist and the arrangement of the image sensor and the analog front end (AFE) differs according to the type of the scanner, the length of a wire by which the image signal output from the image sensor is transferred (load capacity of image signal) differs for each scanner. For this reason, heretofore, a general-purpose image sensor that can be applied to various types of scanners has high drive capability, which is needed to drive an envisioned maximum load.
However, since the driving load of the image sensor is relatively small depending on the arrangement relationship of the image sensor and the analog front end (AFE), there are also cases where the drive capability of the image sensor is excessive, and thus there has been a risk that excessive power consumption will occur, and excessive noise accompanying signal transfer will occur.